Testing the effects of Aerodynamics on film canister rockets made out of Alka-Seltzer
William, Adan
Introduction
For our project we decided to make Alka- Seltzer rockets made out of film canisters. We decided to calculate their height based on 2 different variables. First the normal film canister was used by itself with the mixture of water and alka-seltzer inside. Then for the second set of data, films canisters with a triform fin model glued on were used. This experiment tested out the aerodynamics of rockets and see what effects the fins would have on the height. The fins and shape of the rocket (canister) caused different forms of drag. An example was induced drag which generated lift . Aerodynamics work differently on rockets than planes. On planes lift overcomes weight, but on rockets thrust is what overcomes weight. Due to the rockets center of gravity aerodynamic forces cause rockets to rotate during flight.
Procedure
According to previous experiments (Home Made Rockets,2011), we used the ratio of 1.59 g of Alka-Seltzer, which was about half a tablet, to 10 ml of water. We measured the tablets on a scale, and used a 10 ml graduated cylinder to measure the water. We put the ratio of water and Alka- Seltzer inside empty film canisters. We put the water inside the canister, then the alka seltzer, then we sealed the canister and set it on the ground. After six trials, we then attached three balsa wood fins and glued them to the canister. After each trial, we timed the amount of time it took for the rocket to go off until it hit the ground. We did a total of 12 trials 6 without fins, and 6 with the triform fins.
Getting ready for take off:
Rocket in the Air!!!
Results
At first the film canisters would not hold the pressure so we had to get new ones that would hold the pressure. This is the In flight time of the rockets
Unmodified Rockets
Trial
Time
1
1.69 sec
2
1.66 sec
3
2.06 sec
4
2.09 sec
5
2.25 sec
6
2.45 sec
Triform Fins Rockets
Trial
Time
1
1.57 sec
2
1.69 sec
3
1.43 sec
4
1.72 sec
5
1.44 sec
6
1.83 sec
Conclusions
Even though the fins help with aerodynamics the added weight is to much for the small rocket to overcome. We did however observe that the fins on the rocket caused the rocket to rotate and fly strait and that it would not veer off until it reached it's max height and began to fall in a parabola shape. This would lead us to believe that if we upped the pressure in both rockets the fined ones would go higher because of the aerodynamics.
Table of Contents
William, Adan
Introduction
For our project we decided to make Alka- Seltzer rockets made out of film canisters. We decided to calculate their height based on 2 different variables. First the normal film canister was used by itself with the mixture of water and alka-seltzer inside. Then for the second set of data, films canisters with a triform fin model glued on were used. This experiment tested out the aerodynamics of rockets and see what effects the fins would have on the height. The fins and shape of the rocket (canister) caused different forms of drag. An example was induced drag which generated lift . Aerodynamics work differently on rockets than planes. On planes lift overcomes weight, but on rockets thrust is what overcomes weight. Due to the rockets center of gravity aerodynamic forces cause rockets to rotate during flight.
Procedure
According to previous experiments (Home Made Rockets,2011), we used the ratio of 1.59 g of Alka-Seltzer, which was about half a tablet, to 10 ml of water. We measured the tablets on a scale, and used a 10 ml graduated cylinder to measure the water. We put the ratio of water and Alka- Seltzer inside empty film canisters. We put the water inside the canister, then the alka seltzer, then we sealed the canister and set it on the ground. After six trials, we then attached three balsa wood fins and glued them to the canister. After each trial, we timed the amount of time it took for the rocket to go off until it hit the ground. We did a total of 12 trials 6 without fins, and 6 with the triform fins.
Getting ready for take off:
Rocket in the Air!!!
Results
At first the film canisters would not hold the pressure so we had to get new ones that would hold the pressure. This is the In flight time of the rockets
Conclusions
Even though the fins help with aerodynamics the added weight is to much for the small rocket to overcome. We did however observe that the fins on the rocket caused the rocket to rotate and fly strait and that it would not veer off until it reached it's max height and began to fall in a parabola shape. This would lead us to believe that if we upped the pressure in both rockets the fined ones would go higher because of the aerodynamics.
References
http://pisci.wikispaces.com/AlkaSeltzerRockets
http://exploration.grc.nasa.gov/education/rocket/rktaero.html
http://dthrocket-articles.blogspot.com/2008/04/improving-aerodynamics-5-types-of-drag.html
http://www.apogeerockets.com/technical_publication_16.asp